Induction of Virus-Specific Cytotoxic T Lymphocytes as a Basis for the Development of Broadly Protective Influenza Vaccines

Table 1

Evidence for cross-reactivity of influenza virus-specific CTL.

Subtype			Comments	Ref.
Priming subtype	Cross-reaction with	Species
H2N1	H3N2	Mouse	Cross-reactivity confirmed in Cr-release assays using cultured splenocytes of primed mice	[28]
H1N1	H2N2; H3N2	Mouse	Cross-reactivity confirmed in Cr-release assays using splenocytes of primed mice	[24]
H3N2	H1N1	Mouse	Target cells expressing NP from H1N1 recognized by cultured splenocytes from primed mice	[29]
H3N2	H1N1	Mouse	Cross-reactive cultured splenocytes recognize inner proteins of influenza A virus	[30]
H3N2	H1N1	Human	Cross-reactive CTLs recognize NP, M1, or PB2	[31]
Seasonal influenza	H5N1	Human	Cross-reactive CTLs were detected in the blood of healthy human subjects not exposed to H5N1 virus	[32–34]
pH1N1	H1N1	Human	T cells specific for the NP418 epitope induced by the 2009 pH1N1 cross-react with the 1918-H1N1 variant but not with contemporary variants	[35]
Seasonal influenza	2009 pH1N1	Human	Cross-reactive CTLs were detected in the blood of healthy human subjects not exposed to 2009 pH1N1 virus	[36]